EARNINGS (LOSS) PER SHARE (Antidilutive securities excluded from the computation of earnings (loss) per share) (Details) - shares	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents and outstanding stock options excluded from the calculation of diluted earnings (loss) per share (in thousands)	1,189,000	1,189,000	1,189,000	1,089,000	604,000	299,000	548,000	1,345,000	1,188,933	603,500	556,000
Unvested restricted stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents and outstanding stock options excluded from the calculation of diluted earnings (loss) per share (in thousands)									0	0	350,000
Unvested restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents and outstanding stock options excluded from the calculation of diluted earnings (loss) per share (in thousands)									1,088,933	480,000	0
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents and outstanding stock options excluded from the calculation of diluted earnings (loss) per share (in thousands)									100,000	123,500	206,000